The most common storage battery, found in almost every automotive vehicle, is the lead-acid battery. This battery comprises a lead dioxide positive electrode, a lead metal negative electrode, and sulfuric acid for the electrolyte. An improved design of this battery is disclosed in U.S. Pat. No. 3,862,861.
A number of alternatives to the lead-acid battery have been developed over the years for use in other applications. Two of these alternative batteries employ zinc as the negative electrode and caustic potash as the electrolyte. The positive electrode of one battery is nickel oxide and the other uses silver oxide. (U.S. Pat. No. 1,955,115).
In an effort to combine the best features of the lead-acid battery and the proven alkaline batteries, a lead-zinc battery was developed. Described in a co-pending application, this battery has positive electrode of lead, a negative electrode of zinc, and an alkaline electrolyte. In order to minimize potential corrosion problems, various buffers are incorporated into the electrolyte. These buffering agents include carbonates, borates, silicates, and phosphates.
While effective in achieving the stated purpose, these proposed buffers have serious drawbacks, namely, their limited solubilities. This restriction seriously reduced the capability of the lead-zinc battery by increasing the internal resistance of the battery.
Therefore it is an object of the present invention to provide an improved storage battery that avoids the limitations of the prior art. These and other objects, features and advantages of the invention will be recognized from the following description.